Science and Technology on Plasma Physics Laboratory

Mianyang, China

Science and Technology on Plasma Physics Laboratory

Mianyang, China

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He Y.,China Academy of Engineering Physics | Luo J.,China Academy of Engineering Physics | Li K.,China Academy of Engineering Physics | Luo B.,China Academy of Engineering Physics | And 5 more authors.
RSC Advances | Year: 2016

Beryllium carbide (Be2C) films were first deposited on optical quartz substrates by DC reactive magnetron sputtering on a beryllium target with variable CH4-Ar ratios. The influence of CH4-Ar ratios on the composition, microstructure and optical properties were investigated by X-ray photoelectron spectroscopy, X-ray diffraction, high-resolution transmission electron microscope, atomic force microscopy, scanning electron microscope and UV-vis spectrum. The main component in the films prepared at lower CH4-Ar ratios (<5%) was Be2C, while hydrocarbon (CH) films were formed at higher CH4-Ar ratios (>15%). The films exhibited a nanocomposite structure consisting of Be2C nanocrystals (3 to 5 nm in size) embedded in amorphous hydrocarbon matrices. A smooth surface and columnar structure on the cross-sectional view were revealed. Besides, the depositing rates reached ∼125 nm h-1, which were significantly higher than that of RF reactive magnetron sputtering. High transparency (>50%) of the Be2C films in the visible region as well as an even higher transparency (>80%) in the near-infrared region were demonstrated. Finally, the dispersion of the optical constants of Be2C films is presented, and the optical bandgaps were evaluated to be ∼2 eV. The good properties of Be2C films prepared by DC reactive magnetron sputtering showed that this material could be a potential candidate for application to inertial confinement fusion targets. © The Royal Society of Chemistry 2016.


Luo B.C.,China Academy of Engineering Physics | Luo B.C.,Science and Technology on Plasma Physics Laboratory | Li K.,China Academy of Engineering Physics | Tan X.L.,China Academy of Engineering Physics | And 6 more authors.
Journal of Alloys and Compounds | Year: 2014

The Be coating grown on K9 substrate are fabricated at different annealing temperatures by dc magnetron sputtering, and they are composed of α-Be phase with hcp structure from XRD analysis. As the in situ annealing temperatures increase from 60 °C to 410°C, the coating surfaces show the transition from fibrous grains dominated by surface diffusion to diamond-like grains, and then to recrystallized grains dominated by bulk diffusion. For the coating cross-section morphologies, they are always characterized by the coarsening columnar grains with distinct boundaries. Both surface roughness and grain size increase with annealing temperatures, and obey the modified Anelli model. Moreover, the constitutive relationship of Be coating was explored. The residual stress is related closely to the microstructures and annealing temperatures, not only displays the tensile stress but also compressive stress. The compression-tension transition temperature occurs near 250°C (0.34T m), which is just recrystallization transition temperature. The film electrical resistivity values decrease gradually with the increase of grain size due to the reduction of grain boundary. © 2014 Elsevier B.V.


Mu J.,China Academy of Engineering Physics | Mu J.,Science and Technology on Plasma Physics Laboratory | Jing F.,China Academy of Engineering Physics | Jing F.,Science and Technology on Plasma Physics Laboratory | And 9 more authors.
Zhongguo Jiguang/Chinese Journal of Lasers | Year: 2014

Stochastic parallel gradient descent (SPGD) is an effective way to achieve multi-channel phase-locked laser beams for coherent beam combination (CBC). In this paper, the influence of piston error and tilt error on CBC is primarily presented. Then, an arrangement model of 2×2 laser beams is built. With this proposed model, SPGD is tested and verified. Key parameters, the gain coefficient and the disturbance amplitude, impacts on the error control performance of the algorithm, are analyzed and optimized. The surveys show that it is necessary to control piston error and tilt error for CBC. When SPGD is used to correct the above errors, the convergence speed of the algorithm is improved with the increase of the gain coefficient and the disturbance amplitude, however, the accuracy of SPGD is reduced and the system is vibrated. In order to improve CBC, the adaptive gain coefficient is studied. Compared with the fixed gain coefficient, the adaptive gain coefficient is able to make a good balance between the convergence speed and the accuracy of the algorithm, which indicates that the adaptive gain coefficient is an effective optimization way. These results in this paper provide a theoretical reference for CBC using SPGD in a large short-pulse laser facility.


Wu Z.,China Academy of Engineering Physics | Wu Z.,Science and Technology on Plasma Physics Laboratory | Zuo Y.,China Academy of Engineering Physics | Zuo Y.,Science and Technology on Plasma Physics Laboratory | And 7 more authors.
IEEE Transactions on Plasma Science | Year: 2014

The effect of plasma wavebreaking has been proposed to obtain single-pulse output for backward Raman amplification in plasma. However, some experiments indicate that the scheme may not be effective. In this paper, we propose the effect of Landau damping for this purpose. According to the theoretical analysis, the single pulse is generated by setting a proper plasma temperature to fully Landau damp the secondary spikes. Although the main pulse will also be partly suppressed by the damping, the effective efficiency can be enhanced. Moreover, the scheme is numerically demonstrated feasible by using the parameters of Princeton experiment [1], [2]. Additionally, the temperature to produce single-pulse output can keep below the critical temperature at various ratios of the plasma frequency to the pump pulse frequency. © 1973-2012 IEEE.


Yang B.,China Academy of Engineering Physics | Niu G.,China Academy of Engineering Physics | Niu G.,Science and Technology on Plasma Physics Laboratory | Liu X.-D.,China Academy of Engineering Physics | And 7 more authors.
RSC Advances | Year: 2016

Polymethylmethacrylate (PMMA) composite fibers with micro/nanowire arrays of polystyrene (PS) fibers embedded were prepared by an iterative melt co-drawing and bundling technique. With section-cutting of the PMMA/PS fiber and the dissolution of inner PS, porous PMMA templates were obtained. The pore diameters and spacings of the template can be controlled by this method. The optical microscopy and scanning electron microscopy (SEM) pictures showed that the diameters of the pores were several microns and the spacings of pores were several tens of microns after the second drawing step. The diameters of the pores after the third drawing step were about 310 nm, and the spacings of pores were 2.30 μm. Then, size control of the Cu micro/nanowire arrays could be achieved by electrochemical deposition technology using this template. The SEM results indicated that the obtained diameters and spacings of the Cu micro/nanowires were in accordance with the size of the template. The obtained lengths of the Cu microwires could reach about 30 μm, which depended on the thickness of the PMMA template and parameters of the electrochemical deposition. Significantly, owing to the simple process and good controllability, various micro/nano array materials can be designed and constructed according to the application requirements by using this method. © 2016 The Royal Society of Chemistry.


Li B.,Southwest University of Science and Technology | Li B.,China Academy of Engineering Physics | Niu G.,China Academy of Engineering Physics | Yi Y.,Southwest University of Science and Technology | And 4 more authors.
Guang Pu Xue Yu Guang Pu Fen Xi/Spectroscopy and Spectral Analysis | Year: 2016

To research surface-enhanced Raman scattering effect of different diameters' polystyrene nanospheres (Ag-coated) substrates, we had prepared a new surface-enhanced Raman scattering substrate. It was prepared by using spin-coating and self-assembled to form monolayer and hexagonal close-packed (HCP) order colloidal-crystal films with PS nanospheres of different diameters. Then, a 30 nm Ag film was deposited on the PS arrays with magnetron sputtering. We detected Raman scattered spectrum by means of Roman spectroscopy instrument with Rhodamine R6G as a probe molecule, and the conclusion was drawn that all the substrates of Ag-coated PS nanospheres displayed stronger Raman enhancement. With the increase of the diameter of the microspheres, the degree of fluctuation of polystyrene nanospheres array was continuously strengthened (increasing roughness), and the SERS signal was enhanced gradually. The signal peak reached a maximum when the ball diameter was 600 nm, and then we aquired an optimal SERS substrate. Simultaneously, we found that the SERS spectra of R6G of a high signal to noise ratio was obtained on the substrate, and associated with the benzene ring within a range of C=C double bond stretching vibration characteristic spectrum and the inner surface and the outer surface deformation vibration characteristic spectra were significantly enhanced. The single and large-scale Raman scattering substrate presents especial nanostructure of high and low distribution. The depth and the gap between different PS microspheres show the obvious differences, which can significantly improve the surface morphology structure of Ag film and Raman scattering effect of PS nanospheres substrate. The substrate presenting special arrays' structure has significantly great potential in exploring molecule of chemical and biological filed. © 2016, Peking University Press. All right reserved.


Zhang Z.M.,Science and Technology on Plasma Physics Laboratory | Zhang B.,Science and Technology on Plasma Physics Laboratory | Hong W.,Science and Technology on Plasma Physics Laboratory | Yu M.Y.,Zhejiang University | And 4 more authors.
Plasma Physics and Controlled Fusion | Year: 2016

Generation of ultra-short betatron x-rays by laser-accelerated electron beams is of great research interest as it has many applications. In this paper, we propose a scheme for obtaining bright betatron x-rays by applying external wiggler magnetic field in the laser wakefield to resonantly drive the betatron oscillations of the accelerated electrons therein. This results in a significant enhancement of the betatron oscillation amplitude and generation of bright x-rays with high photon energy. The scheme is demonstrated using two-dimensional particle-in-cell simulation and discussed using a simple analytical model. © 2016 IOP Publishing Ltd.


Zhang Z.M.,Science and Technology on Plasma Physics Laboratory | Zhang B.,Science and Technology on Plasma Physics Laboratory | Hong W.,Science and Technology on Plasma Physics Laboratory | Yu M.Y.,Zhejiang University | And 3 more authors.
Physics of Plasmas | Year: 2014

Backward Raman amplification (BRA) in plasmas has been promoted as a means for generating ultrapowerful laser pulses. For the purpose of achieving the maximum intensities over the shortest distances, an envelope matching between the seed pulse and the amplification gain is required, i.e., the seed pulse propagates at the same velocity with the gain such that the peak of the seed pulse can always enjoy the maximum gain. However, such an envelope matching is absent in traditional BRA because in the latter the amplification gain propagates at superluminous velocity while the seed pulse propagates at the group velocity, which is less than the speed of light. It is shown here that, by using self-ionizing plasmas, the speed of the amplification gain can be well reduced to reach the envelope matching regime. This results in a favorable BRA process, in which higher saturated intensity, shorter interaction length and higher energy-transfer efficiency are achieved. © 2014 AIP Publishing LLC.


Yang G.,CAEP - China Academy of Engineering Physics | Yang G.,Science and Technology on Plasma Physics Laboratory | Zhang J.,CAEP - China Academy of Engineering Physics | Zhang J.,Science and Technology on Plasma Physics Laboratory | And 7 more authors.
Qiangjiguang Yu Lizishu/High Power Laser and Particle Beams | Year: 2010

Time-resolved spectra of highly ionized Cr and Ti tracers, which are buried in the inner wall of golden hohlraum, are measured by the streaked crystal spectrometer on the Shenguang II laser facility. The collisional-radiative model is adopted for non-LTE(local thermodynamic equilibrium) population calculations, and configuration-averaged rate coefficients are obtained based on the first-order perturbation theory. Hartree-Fock Slater self-consistent field method is used to calculate electron wavefunctions. The isoelectronic line-ratio of He-α for Cr and Ti tracers is derived in the electron density range of 1019~1022 cm-3. The evolution of time-resolved electron temperature in hohlraum in the process of laser-plasma interaction is deduced by isoelectronic X-ray spectroscopy, and the peak temperature is 2.05 keV.


Niu G.,CAEP - China Academy of Engineering Physics | Niu G.,Science and Technology on Plasma Physics Laboratory | Yang Y.,CAEP - China Academy of Engineering Physics | Liu X.,CAEP - China Academy of Engineering Physics | And 4 more authors.
Qiangjiguang Yu Lizishu/High Power Laser and Particle Beams | Year: 2014

For Z-pinch physical experiment, aluminum cingulum array loads with self-accommodating structure were designed. The cutting technology for aluminum foil was researched by handiwork and laser. The figure and mechanical performance of aluminum cingulum that was cut from aluminum foil were characterized, and the aluminum cingulums that was cut by laser were suitable for aluminum cingulum array loads. The mechanical performance of aluminum cingulum cut by laser was characterized. For a 30 mm×1 mm×5 μm aluminum cingulum, the tensile strength was about 116 cN and the elongation was about 1.3%. Aluminum cingulum array loads with self-accommodating structure were prepared using the aluminum cingulum cut by laser, and the self-accommodating quantity was up to 4.5 mm which could meet the need of "Qiangguang-I" facility physical experiment.

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